Deficits in visuospatial processing including learning and remembering new information are widely reported in chronic alcoholics but poorly understood. Polysubstance abuse is widespread among alcoholics seeking treatment, yet little is known about the residual cognitive effects of abusing other drugs in addition to alcohol. To address these issues, the performance of three subgroups of alcoholics and normal controls (N = 40/group) will be studied on a battery of measures of visuospatial perception, learning and remote memory. The alcoholic subgroups will include subjects who a) abuse only alcohol, b) alcohol and marijuana and c) alcohol In combination with stimulants, depressants and/or opioids (as defined by DSM-III-R criteria). They will be recruited from local inpatient and outpatient treatment facilities. Controls, recruited from the community, will indicate no history of drug use or excessive social drinking. All subjects will be screened for medical, neurological or psychiatric conditions that could affect performance. All subjects will receive a battery of tests intended to isolate deficits in visual scanning and attention, egocentric and allocentric orientation, featural versus configurational analysis, capacity for categorical versus coordinate judgments about spatial relations, and anterograde and remote memory for visuospatial information. Memory tasks are designed to distinguish between impairments arising from lack of availability as opposed to impaired access to visuospatial knowledge and skills. Additional measures of family history of drug and alcohol abuse, history of childhood or adult residual attention deficit disorder, and current level of depression and anxiety will also be obtained on all subjects. The results of this project will contribute valuable knowledge about the processes involved in visuospatial deficits of alcoholics, by identifying possible differences among alcoholic subgroups, and by determining how subject characteristics listed above may modify the cognitive consequences of different patterns of drug and alcohol abuse.